ABSTRAKT

To overcome emission problems of small-scale batch operated combustion systems a new thermal treatment process was developed to incinerate small batches of residues containing precious metals. The thermal treatment of single batches is necessary to start the recycling of the precious metals and to refund the customers delivering the residues. The new process is divided in a pyrolysis and a subsequent oxidation step. With conventional control techniques it was not possible to operate the system reliably with all different types of residues. Fuzzy-logic controllers were combined with new O₂/PIC sensors in order to control the gasification process and to optimize the afterburner for low NO_x operation. The main focus was to maintain a constant release of volatiles during the pyrolysis process.
The emissions of the overall process were reduced considerably. Furthermore, as a result of reduced peak loads by direct control of the pyrolysis, the size of the flue gas treatment systems can be reduced for new plants. The developed control techniques are now ready for application with other batch operated thermal processes.